This invention relates to substituted polybenzazole polymers in various physical forms, such as fibers or films, and shaped articles such as matrix composites and laminates containing these polybenzazole polymers.
Matrix composites, also known as fiber-reinforced composites, are shaped articles comprising a plurality of fibers (the reinforcement) embedded in a plastic (the matrix). Typically, the fibers give strength and/or stiffness to the composite, and the matrix maintains fiber alignment and transfers load around broken fibers. The mechanical properties of these matrix composites are known to depend upon how well the reinforcing fibers adhere to the matrix resin. Therefore, it is desirable to maximize the adhesion between the fibers and the matrix resin.
Multilayer laminates are articles comprising multiple layers of films and other materials adhered together by various adhesives and/or other sealing techniques. Each layer in a laminate contributes a property, such as structural stability or moisture barrier, to the completed laminate. For a laminate to function as designed it is important that all of the layers of the laminate remain adhered to each other throughout the working life of the laminate. Therefore, it is desirable to maximize the adhesion between the layers of a multilayer laminate.
Matrix composites containing polybenzazole fibers have been prepared, and the use of polybenzazole films in multilayer laminates has been investigated, therefore it would be desirable to improve the adhesion of the polybenzazole fibers to the matrix resin in a matrix composite and to improve the adhesion of the polybenzazole film to the other layers in a multilayer laminate.